The Second L((ke AUjOHqiiin, — Tdijlor. 109 
of lake Huron in considerable detail.* He describes a beach 
which descends westward along the south side of Georgian 
bay and southward along the east shore of lake Huron. 
Towards the south its declivit}' decreases and he estimates 
that it passes under lake Huron to a depth of about 20 feet ott" 
Sarnia. Dr. Spencer has traced this beach to Kirkfield, north- 
east of lake Simcoe in Ontario, and I have found it at inter- 
vals as far north as Nortli Bay, and at high altitudes, as is 
recorded in the fifth paper. Dr. Spencer calls the whole extent 
of this shore line the Algonquin beach, and considers it to be 
one continuous feature and of tlie same age throughout. Ap- 
parently he takes no account of the possibility that, in the 
varying vicissitudes of the lakes, beaches of different ages 
might have overlapped. Yet he finds the Algonquin beach 
passing under the present level of lake Huron, suggesting 
clearly that similar relations may have obtained between other 
beaches in the past. Indeed, it seems probable that the Al- 
gonqufn beach is divisible in this way at some point between 
lake Sincoe and North Bay, into two parts of different ages. 
If the plane of the Nipissing beach as it is on the south coast 
of lake Superior and the northern part of lakes Michigan and 
Huron be projected toward the southeast, it passes about 25 
feet under lake Huron at Sarnia and thus comes into very 
close agreement with the southern end of the Algonquin beach ; 
and it also strikes very close to the level of the heav^' sand^^ 
beach of 50 feet at Midland on Georgian bay. The probable 
identity of the low-level shore lines of this region with the 
Nipissing beach is further supported by Dr. Spencer's de- 
scription of their character. He says the country around the 
head of Georgian bay is sandy. The Nipissing beach is nota- 
bly so in many places. He says that along the eastern coast 
of lake Huron the waves are now cutting away the land and 
have in many places removed the bluii's on which the Algon- 
quin beach rests. f This same cut would remove anything 
that might have remained of the Nipissing beach also. Dr. 
Spencer states that the mean rate of rise of the Algonquin 
beach from the southern end of lake Huron to near Southamp- 
*Se(' lust reference above. 
t"l)<>r()rmatioii of thi' Algomiviiii bi'acli."' t'tc.,(n'rrrrc(l to above.) paire 
i:{ 
